Multiply charged ions from iodine laser-produced plasma of medium- and high-Z targets

Maximum charge states of ions registered in the far expansion zone from laser-produced plasma of Al, Co, Ni, Cu, Ta, W, Pt, Au, Pb, and Bi are presented. The Thomson parabola spectrometer was used to display a general view of the ion species of an expanding plasma while detailed ion charge-energy spectra were determined by the cylindrical electrostatic ion energy analyzer. The current densities of highly charged ion groups above 20 mA/cm2 were measured by use of an ion collector at a distance of 1 m from the target. The photodissociation iodine laser system PERUN (λ = 1.315 μm, power density up to 1015 W cm−2) was employed as a drive

Ion production by lasers using high-power densities in a near infrared region

Results are presented of experiments on ion production from Ta targets using a short pulse (350-600 ps in focus) illumination with focal power densities exceeding 1014 Wcm-2 at the wavelength of an iodine photodissociation laser (1.315 μm) and its harmonics. Strong evidence of the existence of tantalum ions with the charge state +45 near the target surface was obtained by X-ray spectroscopy methods. The particle diagnostics point to the existence of frozen high charge states (4 MeV) for the highest observed charge states. A tentative theoretical explanation of the observed anomalous charge state freezing phenomenon in the expanding plasma produced by a subnanosecond laser pulse is give

Studies of plasma and craters produced by the interaction of high-energy sub-nanosecond laser with silver target

The results of measurements of microablation from a silver target irradiated by the high-power PALS laser system in Prague are presented. In this experiment the laser beam of energy of about 110 J in a 400 ps pulse was focused perpendicularly to the massive silver target. The target surface position was changed with respect to the focal spot of the laser beam in the range from -2.5 to 2.5 mm. A set of four ion collectors was used for plasma ion emission measurements. The effect of the laser pulse interaction with the target, i.e. craters and damages formed in the vicinity of the craters, were investigated with the use of scanning electron microscopy (SEM) and optical microscopy methods. The characteristics of the crater were compared with the essential parameters of ion streams emitted from the plasma produced in the same laser shot